From dcb4fcc3617ce32fe74fd72529610ebdc5bb40bf Mon Sep 17 00:00:00 2001
From: philipel <philipel@webrtc.org>
Date: Wed, 11 Dec 2019 16:35:27 +0100
Subject: [PATCH] Execute cached video encoder switching request if encoder
 switching is allowed after the switch request was made.
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Bug: webrtc:10795
Change-Id: Ib045794bf7ecec67812e1fad2ec8db987f6011df
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161943
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30067}
---
 media/engine/webrtc_video_engine.cc          | 11 +++++-
 media/engine/webrtc_video_engine.h           |  2 ++
 media/engine/webrtc_video_engine_unittest.cc | 35 ++++++++++++++++++++
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index e3ac88be1b..1e338d5178 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -735,7 +735,8 @@ void WebRtcVideoChannel::RequestEncoderSwitch(
 
     if (!allow_codec_switching_) {
       RTC_LOG(LS_INFO) << "Encoder switch requested but codec switching has"
-                       << " not been enabled.";
+                       << " not been enabled yet.";
+      requested_encoder_switch_ = conf;
       return;
     }
 
@@ -1642,6 +1643,14 @@ void WebRtcVideoChannel::SetVideoCodecSwitchingEnabled(bool enabled) {
   invoker_.AsyncInvoke<void>(RTC_FROM_HERE, worker_thread_, [this, enabled] {
     RTC_DCHECK_RUN_ON(&thread_checker_);
     allow_codec_switching_ = enabled;
+    if (allow_codec_switching_) {
+      RTC_LOG(LS_INFO) << "Encoder switching enabled.";
+      if (requested_encoder_switch_) {
+        RTC_LOG(LS_INFO) << "Executing cached video encoder switch request.";
+        RequestEncoderSwitch(*requested_encoder_switch_);
+        requested_encoder_switch_.reset();
+      }
+    }
   });
 }
 
diff --git a/media/engine/webrtc_video_engine.h b/media/engine/webrtc_video_engine.h
index 3a0a156e2a..9e0ede95a7 100644
--- a/media/engine/webrtc_video_engine.h
+++ b/media/engine/webrtc_video_engine.h
@@ -590,6 +590,8 @@ class WebRtcVideoChannel : public VideoMediaChannel,
       RTC_GUARDED_BY(thread_checker_);
 
   bool allow_codec_switching_ = false;
+  absl::optional<EncoderSwitchRequestCallback::Config>
+      requested_encoder_switch_;
 
   // In order for the |invoker_| to protect other members from being destructed
   // as they are used in asynchronous tasks it has to be destructed first.
diff --git a/media/engine/webrtc_video_engine_unittest.cc b/media/engine/webrtc_video_engine_unittest.cc
index b3d36084cf..975761123a 100644
--- a/media/engine/webrtc_video_engine_unittest.cc
+++ b/media/engine/webrtc_video_engine_unittest.cc
@@ -2362,6 +2362,41 @@ TEST_F(WebRtcVideoChannelBaseTest, RequestEncoderSwitchIncorrectParam) {
   EXPECT_THAT(codec.params, Contains(Pair(kParam, kPing)));
 }
 
+TEST_F(WebRtcVideoChannelBaseTest,
+       RequestEncoderSwitchWithConfigBeforeEnabling) {
+  const std::string kParam = "the-param";
+  const std::string kPing = "ping";
+  const std::string kPong = "pong";
+
+  cricket::VideoSendParameters parameters;
+  VideoCodec vp9 = GetEngineCodec("VP9");
+  vp9.params[kParam] = kPong;
+  parameters.codecs.push_back(vp9);
+
+  VideoCodec vp8 = GetEngineCodec("VP8");
+  vp8.params[kParam] = kPing;
+  parameters.codecs.push_back(vp8);
+
+  EXPECT_TRUE(channel_->SetSendParameters(parameters));
+
+  VideoCodec codec;
+  ASSERT_TRUE(channel_->GetSendCodec(&codec));
+  EXPECT_THAT(codec.name, Eq("VP9"));
+
+  webrtc::EncoderSwitchRequestCallback::Config conf{"VP8", kParam, kPing};
+  channel_->RequestEncoderSwitch(conf);
+
+  // Enable codec switching after it has been requested.
+  channel_->SetVideoCodecSwitchingEnabled(true);
+
+  // RequestEncoderSwitch will post a task to the worker thread (which is also
+  // the current thread), hence the ProcessMessages call.
+  rtc::Thread::Current()->ProcessMessages(30);
+  ASSERT_TRUE(channel_->GetSendCodec(&codec));
+  EXPECT_THAT(codec.name, Eq("VP8"));
+  EXPECT_THAT(codec.params, Contains(Pair(kParam, kPing)));
+}
+
 class WebRtcVideoChannelTest : public WebRtcVideoEngineTest {
  public:
   WebRtcVideoChannelTest() : WebRtcVideoChannelTest("") {}